Process for the recovery and purification of uranium deposits



Oct. 14, 1958 J. M. CARTER ET AL 2,856,263

PROCESS FOR THE RECOVERY AND PURIFICATION OF URANIUM DEPOSITS Original Filed April 21, 1944 7 Sheets-Sheet 1 I N V EN TORS James M Car/er Marfin D. flame/7 ATTORNEY J. M. CARTER ET AL 2,856,263 PROCESS FOR THE RECOVERY AND PURIFICATION Oct. 14, 1958 OF URANIUM DEPOSITS Original Filed April 21, 1944 7 Sheets-Sheet 55 mG vR M QQOUMM mm E w 9386 IN VEN TORS James M. Car fer By Marfin 0 Home/7 W4 W- ATTORNEY Oct. 14,1958 M. CARTER ET AL 2,

J. PROCESS FOR THE RECOVERY AND PURIFICATION OF URANIUM DEPOSITS Origlnal Filed April 21, 1944 7 Sheets-Sheet 4 SCRUBB ING. AND WASHING PARTS OF CALUTRON WITH HOT WATER WASH WATER :FCONDENSATE ANDMAKE UP \WATER snevmc SOL/D IMPUR/ TIES WASH WA TER CONDENSING To DISCARD I OXIDIZING LVAGE SOLUTION 0 C Few! Cr!!! 0 4!- TO DISCARD OR SALVAGE EVAPORATING g PRECIPITATING Z/VH OH AND F'LTER'NG gFlLTRA TE TO FURTHER T REATMENT Fig. 4 I

INVENTORS James M Cor fer, BY Mar/7'0 D. Kama/7 A TTORNEY Oct. 14,1958 J. M. CARTER ET AL 2,356,263

PROCESS FOR THE RECOVERY AND PURIFICATION 0F URANIUM DEPOSITS Original Filed April 21, 1944 7 Sheets-Sheet s DISSOLVING URANIUM METAL DEPOSITED ON COPPER COLLECTOR IN COLD HNo (8N) CONDENSATE I AND MAKE UP SOLUTION HNO U0 Cu CONDENSING HN0 EVAPORATI NG CONCENTRA TED PRECIPITATING NH OH AND FILTERING PREClP/TATE NH U 0 TO DISCARD 2 OR SALVAGE r---fi TO FURTHER TREATMENT I N V EN TORS' James M Car/er Mar/"in D. Kama/7 A TTORNEY Oct. 14, 1958 .1. M. CARTER ET AL 2,856,263

PROCESS FOR THE RECOVERY AND PURIFICATION OF URANIUM DEPOSITS Original Filed April 21, 1944 7 Sheets-Sheet 6 STARTING MATERIAL FROM PRIOR PREC/P/MTES TREATMENT (NH )2 07 Fe Oil/ 5 Cr (0 )3 oIssoLvINc 0| so VINc HNO3 HNO s L SOLUTION SOLUT/ON U02 U02 F P C,.+++ c ADJUSTING ADJUSTING [NH4OH P H 2NH4OH P H SOLUTION SOLUTION U02** U0g* Fe*** Fe*** c,-+++ C PRECIPITATING PRECIPITATING TH AND FILTERING {T AND FILTERING #2 3 (/I/mlco PREC/P/TATES Fe (OH) Fe 3 Cr(OH) cam/ TO DISCARD *(NH4)2U2 0, OR SALVAGE I TO oIscARo OR SALVAGE F/L TRA TE F/LTRA TE (NH4)4UO2(C03)3 I v (/I/H,),u0 (co AcIDIFYINc T AND HEATING F SOLUTION 20 3):

F/LTRATE PRECIPITATTNG TW AND FILTERING msc/p/urs NH U 0 2 TO DISCARD FURTHER oR sALvAcE TREATMENT Fig. 6

INVENTORS Original Filed April 21 1944 Oct. 14, 1958 J. M. CARTER- ET AL 3 PROCESS FOR THE RECOVERY AND PURIFICATION OF URANIUM DEPOSITS '7 Sheets-Sheet 7 STARTING MATERIAL 4)2 z r FRoM PRIOR TREATMENT VAPORS CALCINING T H10 GASES g f REDUCING z REACTING co CH4 Y C0 c01 uo uc/ GASES REACTING ggc'z CALCINING GAS (SC/4 x '2 Clz 001 -uc/ RES/DUE (/0; 006/;

SUBLIMING m VACUUM TO SALVAGE jsuauMA'rE 1U (.74

. END PRODUCT Fzlq. 7

INVENTORS James M Coffer BY Mar-fin D. Kama/7 A TTORNEY PROCESS FOR THE RECOVERY AND PURIFICA- TION OF URANIUM DEPOSITS James M. Carter, Los Angeles, and Martin D. Kamen, Berkeley, Calif., assignors to the United States of America as represented by the United States Atomic Energy Commission Original application April 21, 1944, Serial No. 532,159. and this application April 26, 1945, Serial No.

9 Claims. (Cl. 2314.5)

thus enriched for commercial use.

Another object of the invention is to provide a process of producing .an element enriched with a selected isotope, which process utilizes a calutron for the purpose of obtaining the enrichment.

Another object of the invention is to provide a process of producing an element enriched with a selected isotope,

which process utilizes first-stage and second-stage calu trons arranged in tandem for the purpose mentioned.

A further object of the invention is to provide a process of recovering the residue of a material whichhas been subjectedto treatment in a calutron from the parts of the calutron disposed in the source region thereof upon which the residue is deposited.

A further object of the invention is to provide a process of recovering an element enriched with a selected isotope from the collector of a calutron upon which the enriched element is deposited.

A further object of the invention is to provide a process of treating the residue of a material whichhasbeen previously treated in a calutron in order to render the ma:

terial suitable to be retreated in the calutron.

A further object of the invention is to provide a process of treating material which has been enriched with a selected isotope in a first-stage calutron in order torenderi the material suitable to be'further enriched with the selected isotope in a second-stage calutron. A further object of the invention is to provide a process of purifying material which has been treated in first-stage and second-stage calutrons arranged in tandem in order to render the material suitable for commercial use.

A further object of the invention is to-providea process of treating an element which has been impoverished with respect to a selected isotope by treatment in ,a secondstage calutron in order to render the material suitable to be retreated in a first-stage calutron in order again to. enrich the element with respect to the selected isotope.

A further object of the invention is to provide a proc-' ess of producing uranium enriched with U which process utilizes a calutron in which a halide of uranium is treated.

A further object of the invention is to provide a process of producing uranium enriched with U which process utilizes first-stage and second-stage calutrons in which the compound UCl, is treated.

A still further object of the invention is to provide a hired States Patent [0 2,856,263 Patented Oct. 14, 1958 ing uranium both in metallic and compound forms in conjunction with the calutron method of enriching the uranium with U whereby minimum handling of the uranium and maximum efficiency of the process are obtained.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawings, in which Figure 1 is a perspective view, partly broken away, of a calutron that is suitable for use in carrying out the process of the present invention; Figs. 2 and 3 taken together, when arranged end to end, illustrate the overall flow diagram of the present process; Fig. 4 illustrates in greater detail a portion of the flow diagram of the present process, indicating the recovery of the residue of UCL, from the parts of the calutron disposed in the source region thereof upon which it is deposited, and the initial steps of the subsequent purification of the uranium; Fig. 5 illustrates in greater detail another portion of the flow diagram of the present process, indicating the recovery of metallic uranium from the collector of the calutron upon which it is deposited, and the initial steps of the subsequent purification of the uranium; Fig. 6 illustrates in greater detail a further portion of the flow diagram of the present process, indicating the subsequent steps of the purification of the recovered uranium; and Fig. 7 illustrates in greater detail a still further portion of the flow diagram of the present process, indicating the ultimate conversion of the purified uranium back to U01 At the outset, it is noted that a calutron is a machine of the character of that disclosed in the copending application of Ernest 0. Lawrence, Serial No. 557,784, filed 0ctober 9, 1944, now Patent No. 2,709,222, and is employed to separate the constituent isotopes of an element and more particularly to increase the proportion of a selected isotope in an element containing several isotopes in order to produce the element enriched with the selected isotope. For example, the machine is especially useful in producing uranium enriched with U Moreover, in such a machine it is not essential that the material initially introduced be a naturally occurring polyisotope, such as naturally occurring uranium. It is feasible to separate any intermixed or intermingled materials capable of producing ions distinguishable from each other by differences in nuclear mass. Since this is true, it is not essential that the initial material mixtures be made up necessarily of the same chemical elements, as various different elements in intermixed form can readily be separated.

Such a calutron essentially comprises means for vaporizing a quantity of material containing an element which is to be enriched with a selected one of its several isotopes; means for subjecting the vapor to ionization, whereby at least a portion of the vapor is ionized causing ions of the several isotopes of the element to be produced; electrical means for segregating the ions from the un-ionized vapor and for accelerating the segregated ions to relatively high velocities; electromagnetic means for deflecting the ions alongcurved paths, the radii of curvature of the paths of ions being proportional to the square roots of the masses of the ions, whereby the ions are concentrated in accordance with their masses; and means for de-ionizing and collecting the ions of the selected isotope thus concentrated, thereby to produce a deposit of the element enriched with the selected isotope. It will be appreciated that in the event that an element is being separated from other elements, then said element occupies a position with respect to said other elements as said selected isotope occupies with respect to the several other isotopes of the element being enriched with respect to said selected isoprocessof recovering, reclaiming, purifying and convert-J tope.

Referring now more particularly to Fig. 1, there is illustrated a representative example of a calutron 10 of the character noted, which comprises magnetic field structure including upper and lower pole pieces 11 and 12, provided with substantially fiat parallel spaced-apart:

pole faces, and a tank 13 disposed between; the pole faces of the pole pieces 11 and 12. The pole pieces 11 and 12 carry windings, not shown, which are adapted to be energized in order to produce a substantially uniform and relatively strong magnetic field th erebetween', which magnetic field passes through the tank 13 and the various parts housed therein. The tank 13 is of tubular configuration, being substantially crescent-shaped in plan, and comprising substantially flat parallel spaced-apart top and bottom walls 14 and 15, upstanding curved inner and outer walls 16 and 17, and end walls 13 and 19. The end walls 18 and 19 close the opposite ends of the tubular tank 13 and are adapted to be removably secured in place, whereby the tank 13 is hermetically sealed. Also, vacuum pumping apparatus, not shown, is associated with the tank 13, whereby the interior of the tank 13 may be evacuated to a pressure of the order of 10" to mm. Hg. Preferably, the component parts of the tank 13 are formed of steel, the bottom wall thereof resting directly upon the pole face of the lower pole piece 12, and the top wall 14 thereof being spaced at suitable distance from the'pole face of the upper pole piece 11, whereby the top and bottom walls 14 and 15 constitute in effect pole pieces with respect to the interior of the tank 13, as explained more fully hereinafter.

The removable end wall 18 carries an insulator 29 which supports an upstanding charge block 21, provided with a hollow central cavity 22 constituting a charge receiving pocket surrounded by rather thick side walls. Electrical heating elements 23 are embedded in the side walls of the charge block 21 and are adapted to be connected to a suitable source of current, whereby the charge block 21 may be appropriately heated, the charge block 21 being formed of cast steel or the like. Also,

the charge block; 21 is provided with a removable cover,

not shown, and supports a tubular member 24 which in turn supports an arc block 25 formed of carbon or graphite. The are block 25 is substantially C-shaped in plan, an upstanding slot 26 being formed in the wall thereof remote from the charge block 21. Thus, the arc block 25 is of hollow construction, having a central arc cavity 27 formed therein, the arc cavity 27 formed in the arc block 25 communicating through the tubular member 24 with the cavity' 22 formed in the charge block 21.

Also, the removable end wall 18 carries an insulator 28, disposed above the insulator 20, which supports horizontally projecting cathode structure 29, including a fi amentary cathode 30 adapted to be connected, to a suitable source of current. The cathode structure 29 projects over the upper end of the charge block 21, whereby the filamentary cathode 30 overhangs and is aligned with respect to the upper end of the cavity 27' formed in the arc block 25. Further, an anode 31 is arranged, below and in alignment with respect to the lower end of the cavity 27 formed in the arc block 25, the anode 31, being supported by the charge block 21. The filamentary cathode 30 and the cooperating anode 31- are adapted to be connected to a suitable source of current;

Ion accelerating structure, includinga pair of upstanding plates 32 formed of carbon or graphite, is supported by insulating structure, not shown, carried bythe removable end wall 18. The pair of upstanding plates 32 are accelerating structure, including: the plates. 32, for a pur pose more fully explained hereinafter.

The removable end wall 19 carries an insulator 34 which supports an upstanding collector block 35 formed of copper or the like and provided with two laterally spaced-apart cavities or pockets 36 and 37 which communicate with aligned slots 38 and 39 formed in the wall of the collector block 35 disposed remote from the re mo abl nd wall 19. It is noted that the pockets 36 and 37 are adapted to receive two constituent isotopes of an element which have been separated in the calutron 10, as explained more fully hereinafter. Finally, the inner wall 16 carries a number of insulators 40 which support a tubular liner 41 formed of copper or the like, rectangular in vertical cross-section, disposed within the tank 13' and spaced from the walls 14, 15, 16 and 17 thereof. One end of the tubular liner 41 terminates adjacent the accelerating structure, including the plates 32; and the other end of the. tubular liner 41 terminates adjacent the collector block 35; the tubular liner 41 constituting an. electrostatic shield for the high-velocity ions traversing the curved paths between the slit 33 formed by the plates 32 of the ion accelerating structure and the slots 38 and 39 formed in the collector block 35, as explained more fully hereinafter.

In view of the above description, it will be understood that the parts of the calutron 10 carried by the removable end wall 18 constitute a source unit, and the end of the tank 13 disposed adjacent the source unit constitutes the source region of the calutron. Similarly, the parts of the calutron carried by the removable end wall 19 constitute a collector unit, and the end of the. tank 13 disposed adjacent the collector unit constitutes the collector region of the calutron.

Considering now the general principle of operation of the calutron 10, a charge comprising a compound. of the element. to be. treated is, placed in the charge pocket 22 in the charge block 21, the compound of the element mentioned being one which may be readily vaporized. The cover, not shown, is then secured on the charge block 21 and the end walls 18 and 19 are securely attached' to the open ends of the tank 13; whereby the tank 13 is hermetically sealed. The variouselectrical connections are completed and operation of the vacuum pump ing apparatus, not shown, associated with the tank 13 is initiated. When a pressure of the order of 10- to 10- mm, Hg is established within the tank 13, the electric circuits for the windings associated with, the pole pieces 11 and 12 are closed and adjusted, whereby a predetermined magnetic field is established therebetween, traversing the tank'13. The electric circuit for-the heatingelements 23 is closed, whereby the charge in the chargepocket 22 in the charge block 21 is heated and vaporized. The vapor fills the charge pocket 22 and is conducted through the tubular member 24 into the cavity 27 formed in the arc block 25. The electric circuit for the filamentary cathode 30 is closed, whereby the filamentary cathode 30 is heated and rendered electron-emissive. Then the electric circuit between the filamentary cathode 30 and the anode 31 is closed, whereby an arc discharge is struck therebetween, electrons proceeding from the filamentary cathode 30 to the anode 31. The electrons proceeding from the filamentary cathode 30 to the anode 31 break up the molecular form of the compound of the vapor to a considerable extent; producing positiveionsof the element which is tobe enriched'with' a selected one 0 its isotopes.

The electric circuit between the are black 25 and the ion accelerating structure, including the plates 32, is completed, the plates 32 being at a high negative poten-- tial with respect to-the arc block 25, whereby the positive ions are attracted and accelerated to the voltage impressed between the arc block- 25 and the ion accelerating structure. Moreparticularly, thepositive ions proceed from the interior of the cavity 27 formed in the arc block 25.

through the slot 26 formed in the wallthereof, and acrossassessabetween the plate's 32 into the interior of the tubular liner 41. The high-velocity positive ions form a vertical upstanding ribbon proceeding from the cavity 27 formed free path for the high-velocity positive ions, disposed between the plates 32- and the collector block 35 within the tubular liner 41. The high-velocity positive ions entering the adjacent end of the liner 41 are deflected from their normal straight-line path and from a vertical plane, passing through the slot 26 and the slit 33, due to'the effect of the relatively strong magnetic field maintained through the space within the tank 13 and the liner 41 through which the positive ions travel, whereby the positive ions described arcs, the'radii of which are proportional to the square roots of the mass'esof the ions and consequently of the isotopes of the element mentioned. Thus, ions of the relatively light isotope of the element describe and interior arc of relatively. short radius and are focused through the slot 38 into the pocket 36 formed in'the collector block 35; whereas ions of the relatively heavy isotope of the element describe an exterior arc of relatively long radius and are focused through the slot 39 into the pocket 37 formed in the collector block 35.{

Accordingly, the ions of the relatively light isotope of the element are collected in the pocket 36 and are deionized to produce a deposit of the relatively light isotope of the element therein, while the ions of the relatively heavy isotope of the element are collected in the pocket 37 and deionized to produce a deposit of the relatively heavy isotope of the element therein. t

, After all of the charge in the charge pocket 22 formed in the charge block 21 has been vaporized, all of the elec-,

tric circuits are interrupted and the end wall 18 is removed so that another charge may be placed in the pocket 22 and subsequently vaporized in the manner explained;

above. After a suitable number of charges have-been vaporized in order to obtain appropriate deposits of the isotopes of the element in ,the pockets 36 and 37 of the collector block 35, the end wall 19 may be removed and the deposits of the collected isotopes in the pockets 36 and 37 in the collector block 35 may be reclaimed.

Of course, it will be understood that the various dimensions of the parts of the calutron 10, the various electrical potentials applied between the various electrical parts thereof, as well as the strength of the magnetic field between the pole pieces 11 and 12, are suitably correlated with respect to each other, depending upon the mass numbers of the several isotopes ofthe element which is to be treated therein. In this connection, reference is again made to the copending application of Ernest 0. Lawrence for a complete specification of a calutron especially designed for the production of uranium enriched with the isotope U By way of illustration, it is noted that when the calutron is employed in order to produce uranium enriched with U the compound of uranium which is suggested as a suitable charge in the charge block 21 is UCl as this compound may be readily vaporized and the molecular form of the vapor may be readily broken up to form positive ions of uranium with great facility. In this case, uranium enriched with U is collected in the pocket 36 of the collector block 35, and uranium comprising principally U is collected in the pocket 37 of the collector block 35. Also, it is noted that froma practical standpoint, the deposit of uranium collected in the pocket 36 of the collector-block 35 contains considerable amounts of U in view of the fact that this isotope comprises the dominant constituent of ordinary uranium. Furthermore, the deposit of uranium collected in the pocket 36 of the collector block 35 contains a considerably increased amount of U in view of the fact that it is not ordinarily feasible to separate U and U in the production of relatively largequand tities of uranium enriched with U foi' comr'nercial pur-- poses. Accordingly, in this example the uranium deposited in the pocket 36 of the collector block 35 is'considerably enriched, both with U and U and considerably improverished with respect to U 3 as compared to natural or normal uranium.

-During the operation of the calutron 10 in the production of uranium enriched with U the compound UCl;

is vaporized in the charge block 21 and conducted through the tubular member 24 into the cavity 27 formed in the are block 25, where it is subjected to ionization as previously explained. Only a minor fraction (about 5%) of the UCL, vapor is actually ionized in the cavity 27 formed in the arc block 25 and drawn through the slot 26 due to the ion accelerating structure, including the plates 32. The major fraction (about of the UCL, vapor is un-ionized in the cavity 27 formed in the arc block 25 and flows through the slot 26 due to the pressure differential between the cavity 27 and the interior'of the liner 41. This major fraction of the UCl, vapor,

being un-ionized, is not at all alfected by the ion accelerating structure, including the plates 32, and travels into contact with the various parts of the calutron disposed in the source region thereof, upon which parts it is condensed primarily in the compound formUCl, as a residue. More particularly, this residue is condensed principally upon the interior of the adjacent end of the liner 41, but to some extent upon the exterior thereof, the

walls of the tank 13 in the region of the source and upon the exterior surfaces of the various elements of the source unit including the arc block 25, the charge block 21, etc.

More particularly, the minor fraction of the UCl vapor is ionized to form positive atomic ions including U U++, Cl and Cl++; and positive molecular ions including Cl C1 UCI UCl UCl UCl UCl U01 UCl and U0. Of these atomic and molecular ions only the singly ionized atomic ions U+ have the required ratio between mass and charge such that they are focused through the slots 38 and 39 into the pockets 36 and 37 formed in the collector block 35; the atomic ions U+ of masses 234 and 235 focusing through the slot 38 into the pocket 36, and the atomic ion U+ of mass 238 focusing through the slot 39 into the pocket 37, as previously noted.

The doubly ionized atomic ions U++ have such a ratio between mass and charge that they are deflected along an arc of shorter radius into engagement with the inner wall of the liner 41, where they are de-ionized to form a deposit thereon. The singly and doubly ionized atomic ions Cl+ and Cl++ and the singly and doubly ionized mo lecular ions (31 and (31 have such small ratios between mass and charge that they are deflected along arcs of very short radii into engagement with the inner wall of the liner 41 adjacent the source region, where they are de-ionized to form neutral chlorine molecules, which gas is subsequently pumped from the tank 13.due to the operation of thevacuum pumping apparatus previously noted. Similarly, the doubly ionized molecular ions UC1 UCI UCl and UC1++ have intermediate ratios between mass and charge such that they are de fiected along'arcs of intermediate radii into engagement with the inner wall of the liner 41 intermediate the source region and the collector region, where they are de-ionized to form a deposit thereon. Finally, the singly ionized molecular ions UCl UCl UC1 and UCl+ have large ratios between mass and charge, such that they are deflected along arcs of large radii into engagement with the outer wall of the liner 41 intermediate the source region and the collector region, where they are de-ionized to form a deposit thereon.

Accordingly, it will be understood that, after operation of the calutron 10 to vaporize a reasonable number of charges of UCl in the charge block 21, a considerable deposit of UCl. is formed on the adjacent end of the liner in 16,82]. atoms; of a; sample.

4.1,. and] that; a. reasonable deposit. of. me allic; uraninml. as. well. as. the various. uranium; ch orides.v is. formed. n; the; interme iate. portionofitha liner 4.11.. These d ans. s represent. uranium which contains the, rious isotopes U U and: Uztal in. natural. or: normal; amoun s; s ch. that these deposits should be recovered fen-recycling; pur..- poses as; well ,as .to clean. thez. linen 4L and the; QthQKEflIt of the calutron. 10; in. orderto. insure: eflicient: operation. thereof.

Considering. the present proeessin greater.- detail with. reference. to the. production; of unanium enriched with U it. is pointed out that; natural. or normal uranium comprises three isotopes, U? ,.UF and; U inthe approximate relativeabundancesl; 1/139 and 1/ 6;70 n numbers; of; atoms; with. referencev to. U re p i y, or. approximately 16,700,, 12.0; and. 1. atoms, repectiyely, It is highly desirable to prepare large. quantities. of uranium enriched, with, the thermalrneutron.fissionable. isotop.e;.U for, commercial purposes, and it: has been; found, that; this end can be ever, it is desirable that the uranium. product have an enrichment factorwith respect to U of the order of 40.0, this factorbeing defined as. the quotient obtained by dividing the ratio of U to U in the product. with the ratio of U to U in the original material.. Now assuming that the product is enriched by 400 in both U and U it comprises U U and; U in. the approximate relative abundances. 1,. 400/139. and 400/1.6.700 (in numbers of atoms with. reference to U respectively, orapproximately 16,700,. 48.05.;7 and. 400 atoms, respectively, in 65,157 atoms of a sample. Thus the enriched? uranium. product comprises. approximately 25.7% U 73.7% U and.0..6%rU

In order. to obtain. this desired enrichment of? the; uranium. product. by utilizing the. calutronmethod, it has been foundmost convenient. to use: first-stage and. second stage calutrons, the. first-stage calutrons employingnatural. or normal, uranium. and producing, a first-stage enriched producthaving an. enrichment faCiOrgOf' the. order. of 2.0.. with respect to natural. or: normal uranium; and. the second-stage calutrons employing first-stage enriched uranium and producing a. second-stage enriched, product having an. enrichment factor of the order of 20. with re; spect to the first-stage enriched uranium, whereby the secend-stage enriched uranium product,- has a final enrichment factor of. the order of; 4QQWlthIQSPBCt to natural or. normal. uranium. By employing. the present process, whereby the ultimate: enrichment of: the final uranium product is obtained in two stages, asindicated above, each of the first-stage and the second-stage calutrons may be operated in the stable rangeand to give. a maximum yield of enriched material.

Accordingly, in the present. process it will be understood that in the event the calutron comprises a first-stage calutron, the. deposit of. uranium in the pocket. 37 in. the collector block has been impoverished with respect to the desired isotope U and is recovered therefrom and discarded; while the deposit. of uranium in the pocket 36 in the collector block 35 has been singly enriched with respect. to the desired. isotope U and is recovered. therefrom. and, subsequently treated in a second-stage calutron. On, the other hand, in the event the calutron 10 comprises: a. second-stage calutron, the deposit of uranium in the pocket 37. in the collector block 35 has been first enriched and thenimpoverished with respect to. the desired. isotope U and is. recovered therefrom and analyzed for possible recycling in a firststage calutron; while the deposit. of uranium in the pocket 36. in the collector block 35 has been doubly enriched with respect to the desired. isotope U and is. recovered therefrom for commercial. use.

Thus it will be understood that in a first stage calutron, the deposit of metallic uranium inthe pocket 36 in the collectorblock 35 has. been subjected to. one. treatment accomplished by employing. thecalutron method. How.-

and is termed. "singly; enriched uranium, the enrichment being. wi h e pect. to; he i ed. iso op U235; 1.: e; th hand. n a. se ndestag lutron the. deposit of me alli ur nium. in he noeket 36. in. the collector block 35 has been subjected. to. two; treatments, and i termed: dou ly enri he uranium,. the. nri hmerit; h inggrw th resne trto the. desired. isotop U Gonsitierins new the; p sent. proc s n s at rdetailt. nd." referring to he. comp site. flow diagr m. il u t ated in F s-r211 and hit. wilL herunderstood. that; a; plant 3 7-. ranged to carry out: thiQ-PIQCESS; Willcomprisea relatively large: number of: firsttage cahltr ns and. a. rela i y small. numher of seeonthstage:calutronsin addition o. facil iestiol liandl'ina; stories. recoverin p f n nd. converting; the. variousmetallio and; compound. formsof uranium; As illustnatediinz the; diagr ar g: ma terial. employed. as a: charges in the; first-stage. calutron is. UCl comprising natural 0171101111131 uranium, whereby metallic. uranium: singly enriched. with U is depositedi in. theafirste pockets of the collector and. metallic uranium impoverished with, respeemtor U iSr deposited in the second: pocket of: the collector. Also, a large amount of UCl; is'dcpositedi as: at. residue upon the parts of the first-stage-lcalutron" disposed in the source region thereof, the deposit being primarily. on the. source-region end of the liner; Aften-severaleharges ofUClg, comprising natural or normal uranium havebeenemployed in thefirst-stage calutron, reasonable deposits of metallic uranium have! beencollectedin the first and second pockets of the collector, and the metallic uranium deposits i in the: collecton and' the, U61; residue on the liner are recovered; A

"More particularly, the metalli'c; uranium singly enriched with U and deposited in the first pocket of the collector is recovered by an acidwash process, whereby various impurities including copper are introd uced in the wash solution; due to the fact that the collector of the first-stage calutron which isthus washed with acid" is. formed of the metal mentioned. Accordingly; the wash solution containingthe uranium singlyenriched-with U which has been reclaimed contains clonsiderableimpurities; This; wash solution. is stored and subsequently employed as makeup material in a purification process utilized in; conjunction. with the s'econd stagg-calhtrom'in a mannermore fully-explained hereinafter. The metallic; uranium impoverished with respect-to U 'and" dcpositcdfin; thesecond. pocket of. the collector is recovered by an acid wash process and discarded; asi'tcontains solittl'e U and further processing thereof is not feasible.

The residue of U614 deposited. on the parts of .the first-stage calutrons disposed in thesource region thereof, principally upon the liner, is recovered by a water wash process, whereby various impurities including copper,

- iron, chromium, nickel' andcarbon are introduced in the wash solution, due to thefact that the various parts of the first-stage calutron which are. thus washed with water are formed of the materialsmentioned. Accordingly, the wash solution containing natural or normal uranium which has been reclaimed, contains considerable impurities... To. thiswash... solution there is added makeup material, in the. form. of awash, solution derived from the. second-stage calutron, and. comprising the Wash solution. from. the, second. pocket. of. the, collector,. and

q containing. uranium whichhas been first. enriched with steam uranium, whereby metallic uranium doubly enriched with U is deposited in the first pocket of the collector and metallic uranium which has been first enriched in the first-stage calutron and then impoverished in the second-stage calutron is deposited in the second pocket of the collector. Also, alarge' amount of UCL; is deposited as a residue upon the parts of the second-stage calutron disposed in the source region thereof, the deposit being primarily on the source-region end of the liner. After several charges of UCl comprising singly enriched uranium have been employed in the secondstage calutron, reasonable deposits of metallic uranium have been collected in the first and second pockets of the collector, and the metallic uranium deposits in the collector and the UCL; residue on the liner are recovered.

More particularly, the metallic uranium doubly enriched with U and deposited in the first pocket of the collector is recovered by an acid wash process, whereby various impurities including copper are introduced in the wash solution, due to the fact that the collector of the second-stage calutron which is thus washed with acid is formed of the metal mentioned. Accordingly, the wash solution containing the uranium doubly enriched with U which has been reclaimed contains considerable impurities. This wash solution is then purified in order to eliminate the impurities mentioned; the impurities thus eliminated are discarded or salvaged; and the uranium thus purified is converted into a standard compound of uranium for commercial use. The metallic uranium first enriched with U and subsequently impoverished with respect to U and deposited in the second pocket of the collector is recovered by an acid wash process, whereby various impurities including copper are introduced in the wash solution, due to the fact that the collector of the second-stage calutron which is thus washed with acid is formed of the metal mentioned. Accordingly, the wash solution containing the uranium first enriched with U andsubsequently impoverished with respect to U which has been reclaimed contains considerable impurties. The uranium in the wash solution is then analyzed, and in the event it contains at least as much U as natural or normal uranium, it is employed as makeup material in the purification processv utilized in conjunction with the first-stage calutron.

The residue of UCL; deposited on the parts of the second-stage calutron disposed in the source region thereof, principally upon the liner, is recovered by a water wash process, whereby various impurities including copper, iron, chromium, nickel and carbon are introduced in the wash solution due'to the fact that the various parts of the second-stage calutron which are thus washed with water are formed of the materials mentioned. Accordingly, the wash solution containing the singly enriched uranium which has been reclaimed contains considerable impurities. To this Wash solution there is added the previously stored makeup material in the form of the wash solution derived from the first-stage calutron and comprising the acid wash solution from the first pocket of the collector of the first-stage calutron and containing singly enriched uranium. This composite wash solution is then purified in order to eliminate the impurities mentioned"; the impurities th'us eliminated are discarded or salvaged; and the uranium thus purified is then converted back to the compound UCl ployed as a charge in the second-stage calutron.

Accordingly, the residue of UCl deposited in the source region of the second-stage calutron is treated to render it re-cyclable therein; the second-stage enriched uranium isconverted-to a standardcompound. ofuranium to be This compound of UCl, is then em-' used commercially; and thesecond-stage impoverished uranium is stored for use in the first-stage calutron.

Considering now the details of the recovery of the UCL, residue from the parts of either a first-stage or a second-stage calutron disposed in the source region thereof, and the initial steps of the subsequent purification of the uranium thus recovered, reference is made to the portion of vthe'flow diagram illustrated in Fig. 4. The.

parts of the calutron disposed in the source region thereof, principally the source-region end of the liner, are scrubbed and washed with hot water, whereby the residue of UCL; deposited thereon is dissolved; and various impurities, including copper, iron, chromium, nickel and carbon are introduced in the water wash, due to the fact that the various parts of the calutron which are thus washed with the hot water are formed of the materials mentioned. The wash water is then sieved in order to remove any solid impurities which may be picked up, such, for example, as small pieces of metal and carbon. These solid impurities may be either discarded or subjected to salvage treatment in order to recover any occluded uranium. The sieved wash water is then treated with H 0 by adding a slight excess of 10% H 0 and agitating the solution, in order to oxidize the various contained materials. For example, the wash water may contain suspended U(OH); and bits of copper and carbon; dissolved-uranium in the +4 and +6 valence states; as well as dissolved copper, iron, nickel, chromium and possibly other metals in one or more of the positive valence states. Hence, all of the uranium is put in solution as uranyl ion, suspended copper is put in solution as cupric ion, and other dissolved metals are put in solution in their higher stable valence states. Carbon is not oxidized by this treatment. The effect of the oxidation on the various materials contained in the Wash solution may be indicated as follows:

Accordingly, the oxidized wash water contains at least the following: UO Cu++, Fe+++, Cr+++, Ni++ and C (carbon). The oxidized wash water is then filtered in order to remove C which may be discarded or subjected to salvage treatment in order to recover any uranium occluded.

In the event this filtrate is rather dilute, it may be concentrated by evaporation; otherwise, this step is omit ted. In the event the filtrate is concentrated by evaporation, the water vapor which is driven oil is condensed and to it is added enough makeup water in order to pro vide a new wash solution, which is used again towash the parts of the first-stage calutron disposed in the source region thereof, in the manner previously explained. This step, comprising condensing and reusing the water vapor which is driven off the filtrate incident to concentration by evaporation, is advantageous in view of the fact that any uranium entrained in the water vapor is not lost to the outside.

The original filtrate mentioned above, or the concentrated filtrate following evaporation, in the event this step is employed, is then subjected to ammonia treatment, either with excess NH gas or carbonate-free NH4OH, whereby (NH4)2U207, and

are precipitated away from most of the copper and nickel in solution, in the form of ammonia complex ions, Cu(NH and Ni(NH The solution is then filtered and the precipitate consisting of ammonium diuranate, ferric hydroxide and chromic hydroxide is then osages.

washed with, water. containing about 1% NH QH and 1% NH NO in orderv to eliminate.occludedcopper-and nickel ammonia, complex ions. The filtrate. containing the copper. and nicltel; ammonia complex. ions; is. then. discarded orsubjected to. salvage treatment. in order. to recover any. uranium contained; andthe initially; purified. precipitate of (NH U O ,.Ee(QH). aILCLCJ.'(OI )s is then stored for: further treatment,

It will be understoodthat the storedprecipitate derived fromv the parts. of. the first-stage calutron. disposed in the source region thereof, as explained above, comprises. uranium of. natural or normal. composition with reference to U while the stored precipitate derived. from the partsof the secondrstagetcalutron disposed. in,

the; source. region thereof, as explainednbove, comprises,

uraniumwhich is singly enrichedwith U Considering. now the details of the recovery of the: metallic uranium, singlyxenriched. with U from the first pocket of the collector of the first-stage calutron, or of the. metallic. uranium, doubly enriched. with. U fromthe first pocket of the. collector of the second-stage calutron, and the initial steps of the subsequent purification of the'uranium thus recovered, reference is made. to the portion of the flow diagram illustrated in Fig. .5... The inner surfaces of the first pocket of the. collector of the calutron are. etched with HNO about 8N, whereby the deposit of metallic uranium, either singly orzdoubly enriched withU is dissolved; and various impurities, principally copper, are introduced in the; acid wash solu: tion, due. to the fact that thecollector of the. calutronl which is thus etched with nitric acid, is-formedx of. the material mentioned. Accordingly, the wash acid, contains atleastthe following ions: U0 and Cu++..

In the. event this wash, acid. is rather dilute in. these. ions, it may be-concentratedrby evaporation; otherwise,, this step is omitted. In the event the wash acid is concentrated by evaporation, the HNO vapor which is driven off is condensed and to it is addedenough makeup HNO in order to provide a newwash acid, which is again used to wash the first pocket-ofthe collector of the calutron in the manner previously explained. This step, comprising condensing the HNO vapor which is driven off the wash acid incident to concentration by evaporation, is advantageous in view of the fact that any uranium entrained in the HNO vapor is-not lost to the outside.

The original wash acid mentioned above, or the concentrated. wash acid following evaporation, in the event this step is employed, is then subjected to. ammonia. treatment, either with NH gas or carbonate-free NH OH, whereby (NI-LQ U O is precipitated away from most of the copper which remains insolution as ammonia complex ion, Cu(NI-l;;) The solution is then filtered and the precipitate, ammonia diuranate, is then washed with water containing. about 1% NH OH and. 1% NH NO in order to eliminate occluded copper complex ion. The filtrate containing the copper ammonia. complex ion is then subjected to salvage treatment in order to recover any uranium contained. Preferably, the; precipitate of ammonium diuranate, and perhaps a trace of Cu(OI-I) is dissolved in HNO re-precipitated with. NH OH- andre-washed with water containingabout 1% NH OH. and 1% NH NO in. the manner explained above. This solution is then filtered and the filtrate, consisting principally of u(NI-I ion, is then; dis.- carded or subjected to further salvage treatment in order. to recover any uranium contained; and the precipitate of ammonium diuranate is then stored for further treat, ment.

It will be understood that the stored precipitate de-. rived from the first pocket of the collector of the firststage calutron, as explained above, comprises uranium which is singly enriched with U while the stored precipitate derived from the first pocket of the collector of the second-stage calutron comprises uranium which is doubly enriched withU The. metallic. uranium impoverished with respect. to.

1. and. deposited in the secondpocketof the collector. of the firstrstage; calutron: may. be recovered merely. by etching, the inner surfaces of the. secondpocket of;this. collector. with- 8N HNO whereby this. deposit. of metallic. uranium:is..dissolved. This acid wash solutiontis, then.,discarded, as. itcontains so little U that further processing thereof is not feasible,

Onthe. other hand, themetallic uranium which. has. been first. enriched withrespect to U and subsequently impoverished with'..respe.ctto..U anddeposited hither second pocket: of .the. collector of the second-stage caluL- tron, may. be recovered by etching the inner surfacesof the; second. pocket of. this; collector. with 8N HNQ- whereby this deposit of. metallic uranium. is dissolved;.. and. various impurities, principally copper, are. intro duced in the acid wash. solution, due to thefact; that. the. collector: of. the. secondfstage, calutron thus etched; withnitric; acid is formedof: the material mentioned. Accordingly the wash. acid contains at least the following. ions: UO and. Cu.++. The considerations con-. cerning, whether the. wash acid should be concentrated are the same as those previously noted. in any case, either the original wash: acid mentioned. above, or the. concentrated wash acid following. evaporation,..in. the. event this step is. employed, is then. analyzedin order. to determine the U content thereof. Inthe eventthe analysis. indicates that the Ug icontent of. this. wash acid. is1at.least asgreat asnatural or normal; uranium,,. it. is: conserved. for. further treatmentg on the. other hand, in. the event the. analysis. indicates thatthe U? contents of..this wash, acid. is. less. than that. of natural. or :normal. uraniumit. is discarded. as further; processing; thereof; isnot. feasible.

Assumingjhat the. analysisindicates that: the U corra tentrof this.conserved. wash acid is'atleast as great .asz

that-.of natural or nonmahuranium, it is subjected. to ini-- tial, purification by. the. ammonia. process previously dea scribed, whereby a .preciiptate of. (.NH U O isobtained, which. isv then stored, for. furthertreatment.

To the storediplecipitate derived after initial purification fromjthe parts .ofithe firstsstage calutrondisposedlin the. source regionthereof, there-is added the stored precipitate derived after initialpurification from-the second; pocket of the. collector. ofthe. second-stage calutron, in order. to. produce a first. composite. precipitate; this. first composite. precipitate comprises uranium: of substantally natural or. normahcomposition. with reference to U Also, to the stored precipitateden'ved after: initial purification from the parts of the second-stage. calutron disposed in the sourceregion thereof, there is added. the stored precipitate derived after initial purification. from the firstpocket of the collector of, thefirstfstagecalutron, in order-to produce ansecondcomp osite precipitate; this. second composite precipitate comprises uranium which is; singly enrichcd With U Finally, the stored precipitate. derived. after initial purification. from the first pocket of. the. collector of the. second-stage calutron. constitutes a third com-. posite. precipitate; this. thirdv composite precipitate. comprises uraniumwhich isdoubly enriched with U Considering now i the; details. of; the. subsequent. Plll'lfir cation; of one. of: the. composite precipitates. described above, comprising. .(NH U O Fe.(QH) and. Cr( O.H) reference. is, made. to. the. portionof, the; flow diagram illustrated in. Fig. .6.. The, compositeprecipitate is first dissolved in HNOi andthe p H.of the.solution.is adjusted to about 2,. using 6N NH .OH, whereby the. solution contains the. following ions: UOfhEei and Cr+++, the; ions being innthehigher stablewalence states. The solution is then treatedwith,anexcess of a .:NH QH.-. (NH CO reagent,.comprising an approximately saturated solution. of. (-NH CO3 in. 3N NH OH,. whereby Fe(.OI-I and .Cr,( O,H) areprecipitated While theura-- niumi remains in solution; as the :uranyl. carbonate. complex ion. UO (CO T*"-. The. solutiomisthenfilteredi hydroxide may be discarded or subjected to salvage treatment in order to recover any trace of occluded uranium. Also in this case, the filtrate containing the uranyl carbonate complex ion is added back to the original filtrate containing the uranyl carbonate complex ion, and the filtrate is then subjected to further treatment.

In any case, regardless of whether one or more precipitations with NH OH and (NH CO are employed, the filtrate containing (NH UO (CO is acidified with concentrated HNO and heated, in order to break up the uranyl carbonate complex ion to produce UO (NO whereby CO is given ofi from the heated solution. This uranyl nitrate solution is then treated with carbonate-free NH OH, whereby (NH4)2U2O7 is precipitated. The solution is then filtered, whereby the filtrate containing NH NO is discarded or subjected to salvage treatment in order to recover any (NHg U O contained; and the uranium thus purified and in the compound form (NI-I U O is stored for further treatment or commercial use, as previously noted. t It will be understood that the purification of the first composite precipitate in the manner described above is productive of a first batch of (NH U O containing uranium of natural or normal composition with reference to U Also, the purification of the second composite precipitate in the manner described above is productive of a second batch of (NH U O containing uranium which is singly enriched with U Finally, the purification of the third composite precipitate in the manner described above is productive of a third batch of (NH U O containing uranium which is doubly enriched with U The first and second batches of (NH U O are then converted back to UCL, for retreatment in the first-stage and second-stage calutrons, respectively; while the third batch of (NH4)2U2O7 is available for commercial use.

Considering now the details of the ultimate conversion of either the first batch or the second batch of (NI-I U O to UCl reference is made to the portion of the flow diagram illustrated" in Fig. 7. More particularly, a batch of (NH4)2U2O7 is calcined at approximately 300 C. in order to produce U0 whereby NI-I gas and water vapor are given off incident to the calcination. The uranium trioxide thus produced may be converted by alternative processes into crude UCl In accordance with one process, the U0 is first reduced to U0 by heating with CH, at approximately 450 C., as disclosed in the copending application of Milton J. Polissar, Serial No. 494,448, filed July 13, 1943, now Patent No. 2,678,257, issued May 11, 1954, whereby CO and CO gases and water vapor are given off incident to the reduction. The uranium dioxide is then reacted with C01 in the vapor phase at approximately 450 C.. in a suitable reaction chamber, in order to produce crude UCl as disclosed in the copending application of James M. Carter, Serial No. 490,293, filed June 10, 1943, now Patent No. 2,677,592, issued May 4, 1954, whereby COCl CO CO and C1 gases are given ofli incident to the reaction. In accordance with an alternative process, the U0 may be reacted directly with CCl in the liquid phase in an autoclave at a temperature approximately 140 to 160 C. and at a pressure approximately 200 pounds per square inch gauge, in order to produce UCl as disclosedin the copending application of Charles J. Carignan and Ernest C.'

Evers Serial No; 55'/,JJ4,'fileu October 6, 1944, now- Patent No. 2,734,795, issued February 14, 1956, whereby COCI CO CO and C1 gases are given oif incident to the reaction. The uranium pentachloride thus pro duced is then calcined or decomposed to produce crude UCL, by heating to approximately 350 C., whereby C1 gas is given ofi incident to the calcination.

In any case, the crude uranium tetrachloride produced by either of the alternative processes indicated above is then sublimed in a suitable molecular still at approximately 600 C., in order to produce a sublimate of UCl whereby residues of U0 and 'UOC1 are produced incident to the sublimation. The residues of U0 and UOC1 are ultimately converted to UCl The UCL, thus produced is of very pure form and is suitable for recycling in the appropriate one of the first-stage or second-stage calutrons, in the manner previously explained. More particularly, the conversion of the first'batch of (NH U O is productive of a first batch of U01 containing uranium of natural or normal composition with reference to U this first batch of UCL; is recycled in the first-stage calutron. Also, the conversion of the second batch of (NH 2U2O7 is productive of a second batch of IJCL, containing uranium singly enriched with U this second batch of UCl is recycled in the second-stage calutron.

Other examples of detailed chemical procedures which may be followed in order to recover uranium from the parts of a calutron upon which it is deposited, to pur1fy the recovered uranium purities or contaminants, and to reclaim or salvage any uranium carried by the various precipitates and filtrates resulting from purification, are'disclosed in the copending applications of Martin D. Kamen, Serial No. 532,160, filed April 21, 1944, now abandoned; Martin D. Kamen et al., Serial No. 542,378, filed June 27, 1944, now Patent No. 2,771,340, issued November 20, 1956; James M. Carter et al., Serial No. 559,624, filed October 10, 1944; Robert Q. Boyer, Serial No. 552,548, filed September 2, 1944, now Patent No. 2,771,339, issued November 20, 1956; Scott B. Kilner, Serial No. 558,954, filed October 16, 1944; Ross Cummings, Serial No. 532,161, filed April 21, 1944, now Patent No. 2,772,142, issued November 27, 1956; and Sam Rosenfeld, Serial No. 567,- 286, filed December 8, 1944.

In view of the foregoing, it is apparent that there has been provided a process of recovering, reclaiming, purifying and converting uranium, both in metallic and compound forms, in conjunction with the calutron method, whereby uranium enriched with U may be produced on a large scale in commercial quantities.

Also, it will be understood that the present process may be suitably modified so that a compound of uranium other than UCL; may be treated either in the first-stage or in the second-stage calutron. For example, the calutron, as well as theconversion steps of the process, may be modified, whereby UCl UBr etc. may be treated in order to produce uranium enriched with U Furthermore, it will be understood that the present process may be further modified in order to accommodate the enrichment of other elements in one or more of their isotopes. For example, potassium may be enriched with respect to the radioactive isotope K4", rubidium with respect to the radioactive isotope Rb, or samarium with respect to the'radioactive isotope 8m Further, it will be understood that the present process contemplates subjecting the element that is to be enriched with respect to-a selected one or more of its isotopes to successive calutron treatments until the element contains the desired enrichment of the selected one or more of its isotopes, whereby the process may in fact be carried out in three or the required number of calutrons, arranged in tandem relation.

The term uranium is employed in the present specification and claims in a generic sense, i. e., as applythus eliminating the metal im-,

ing; to uranium whether in elemental, combined. or ionic form, unles'srindicated otherwise by the context.

While.there has been described what. is at present. considered to be thepreferred. embodiment of the invention,,it will be understood that various modifications may be made therein and it is intended to cover. in.the appended claims allv such modifications asfall within, thgtruewspirit and scope of. the invention.

Whatis claimedis:

1. The? process of recovering uranium'values from deposits formed on. the-.partsofacalutron as a result ofthe processing of UCL; therein,.comprising, washing said parts to an aqueous wash solution containing. said uranium values together withimpurities of. a.first class.

including nickel. and copper ions. which form: soluble complexiions' in the presence of" ammonium. hydroxide and impurities of a second. class including iron and chro mium ions which form insoluble hydroxides. inthe pres-'- ence-o-i ammoniumrhydroxidecfand mixtures of ammonium hydroxides and ammonium carbonate, treating the;washt solution with an oxidizing agent, treating the: oxidized wash solution with ammonia. toprecipitate theuranium.

values as (NH U O and thermetal. impurities: of the.

second class as hydroxides away from the. metal 1 impurities of the first class remaining as solublelammonium.

complex ions in the solution, filtering the. solution 3 in order to separate the (NH J U O and the: metal? hydroxide precipitates from the metal impurities-ofathe firstclass in the filtrate, dissolvingthe. (NHQ U OF andmetal hydroxide precipitates in acid, treating: thetacid: SO'llliiOnr with ammonia and ammoniumwarhonate to'precipitater: the metal impurities of the: second: class asi hydroxides.

away from the uranium in the solution; andwtlrent filter ing the solution in order to separate the; precipitatemf. metal hydroxides from the-uranium valuesiiinethe filtrate:

2'. The process of reclaiming uranium values fromv deposits formed in a calutron as a resultrofiprocessing UCL, therein, comprising removing said-deposits: from said calutron, forming an aqueous solution fromsaid deposits; treating said solution with ammonia to tprecipiltate (NH U O therefrom inpurified form, calcining. said (NH U O to-produce U chlorinating saidflUOg: to produce UCl converting-said UCl into U01 and purifying said UCL; to be recycled in the calutron;

3. The process of recovering uranium values 'from deposits formed on the parts ofal calutron disposed in the source region thereofas aresult' of the-processing of a halide compound of uranium therein, comprising washing said parts with water to form a s'olutiont containing said values and metal impurities including copper and nickel ions which form alkaline soluble ammonium complex ions, treating said solution with an ox idizing agent, adding ammonia to precipitate said uranium values, while said impurities remain in solution as ammonium complex ions, separating the uranium values from said solution, calcining said precipitateto pro-duce uranium oxide, and halogenating'the oxide-to reconstitute said uraniumhalide compound.

4. The process of recovering uranium values from deposits formed on the parts of a. calutron disposed in the source region: thereof as a result of processing a uranium halide compound therein, comprising washing said deposits with water to form a solution containing said values and metalximpurities including; ironti and' Iii depositsI formed on.the partsnof aicalutron, disposed in the source. region. thereof. as a result of processing a uranium halide compound therein, comprising washing said parts with water to form a solution containing said uranium: values together. with metal impurities including nickel and copper ionswhich form soluble ammonium complex; ions in alkaline solution and; impurity ions ineluding-, ironi and chromium which form insoluble hydroxides: in mixed. ammonium. carbonate-ammonium hy droxid'e and ammonium hydroxide solutions, oxidizing said solution with: anagent therefonadding ammonia to saidl oxidized solution to precipitate said' uranium values; and said impurities including. iron. and chromium insoluble: in,said1 solutionand away from the copper and nickel. impurities remaining as soluble ammonium. complex. ions in the solution, dissolving said precipitate inacid, treating said solution with ammonia and. ammonium carbonate to precipitate said impurities including iron and. chromium; away from the uranium values remaining.inwthesolution, acidifying the solution containingathe: uranium values,, addingammonia to said acidified solution to. precipitateiuran'ium values therefrom, calcining, said precipitate to uranium oxide,,and halogenating said oxide: to reconstitute said uranium halide compound.

6:.The: process of! recovering uranium values from deposits. formed on: the collector of a. calutron as a result of: the processingiof a uranium material. therein, comprising washingrsaid collectorto produce a solution containing: said. uranium values and copper, oxidizing; said solution. with an agent therefor, treating said oxidized solutionwith ammonia to precipitate said uranium values as (NH U O calcining said (NH4)2U2O7 to produce- U0 convertingtsaid; U0 to UCl and purifying said U61 7. The processsofrecovering uranium values from. deposits formed on:the parts=of a calutronl as-aresult of theprocessing of UCL, therein, comprising. Washing said parts. with an aqueous solvent'to form a solution contain;- ingsaid. values and impurities including iron and chromium ions whichv form insoluble hydroxides. in the presence of. ammonium carbonate and ammoniumhydroxide', oxidizing: said solution with an agent therefor, treating said oxidized solution with ammonia and ammonium; carbonate to. precipitate said impurities, and:

filtering, said solution to remove said precipitaterand leave said uranium values in solution- 8. The process asin claim 7 with the additionalstep of. adjusting thepH ofsaid oxidized solution. toa' value ofabout 2, prior to saidprecipitation step.

9; The process of recovering uranium values from deposits formed on the parts of a calutron' as a result of the processing of a uranium material therein, comprising washingsaidlparts to form. an aqueous solution containing said-values andlimpurities including. iron and chromium ions. which form insoluble hydroxides in the presence of ammonium carbonate and. ammonium hydroxide, oxidizing'said solution with hydrogen peroxide, treating said oxidized'lsolution with ammonia and ammonium carbonate. toprecipitate saidimpurities and leave said uranium values in solution, filtering said solution to remove said precipitate, and adding HNO to said'filtrate to produce UO (NO -therein.

References Cited in the file of this patent UNITED STATES PATENTS 1,081,949 Du Pont Dec. 23, 1913 1,461,067 Moser July 10,1923 1,463,154 Cummins July 31, 1923 OTHER REFERENCES Friend: Textbook of Inorganic Chemistry, vol. VII,

part III, page 294 (1926), publ. by Charles Grifiin &Co., Ltd., London. 

1. THE PROCESS OF RECOVERING URANIUM VALUES FROM DEPOSITS FORMED ON THE PARTS OF A CALUTRON AS A RESULT OF THE PROCESSING OF UCL4 THEREIN, COMPRISING WASHING SAID PARTS TO AN AQUEOUS WASH SOLUTION CONTAINING SAID URANIUM VALUES TOGETHER WITH IMPURITIES OF A FIRST CLASS INCLUDING NICKEL AND COPPER IONS WHICH FORM SOLUBLE COMPLEX IONS IN THE PRESENCE OF AMMONIUM HYDROXIDE AND IMPURITIES OF A SECOND CLASS INCLUDING IRON AND CHROMIUM IONS WHICH FORM INSOLUBLE HYDROXIDES IN THE PRESENCE OF AMMONIUM HYDROXIDE AND MIXTURES OF AMMONIUM HYDROXIDES AND AMMONIUM CARBONATE, TREATING THE WASH SOLUTION WITH AN OXIDIZING AGENT, TREATING THE OXIDIZED WASH SOLUTION WITH AMMONIA TO PRECIPITATE THE URANIMUM VALUES AS (NH4)2U2O7 AND THE METAL IMPURITIES OF THE SECOND CLASS AS HYDROXIDES AWAY FROM THE METAL IM- 